University of Vermont Extension
Department of Plant and Soil Science

Pinching
back annuals and late-blooming perennials, tending to strawberries
regularly,
and edging beds are some of the gardening activities for this
month.

It's a
good idea to “pinch” or prune back many annual flowers, such as
coleus, petunias,
snapdragons, zinnias, impatiens, and salvia, early in the season and
again
whenever they start getting leggy. Pinching encourages the side buds
to grow so
you'll get more flowers. Pinch just above a node on the stem where
leaves
attach. The lower you pinch on the plant, the bushier it will
become, but a low
pinch often will reduce the ultimate height of the plant.

Pinch back
late-season flowering perennials, such as phlox, asters, Helen’s
flower, Joe
Pye, and Russian sage, now for shorter and fuller plants. Extend the
bloom time
by pinching half of them, because the pinched ones will bloom a few
weeks later
than the unpinched ones. Remove the top one-third of shoots.

Once early
summer perennials, such as peonies and foxgloves, have finished
blooming, take
the time to clip off the spent flowers to spare the plant the energy
it would
spend on forming seeds. Don’t clip old
flowers if you plan to save the seed and do some propagating of your
own, or
leave the seeds for birds. For seed collecting, leave some seedheads
until they
turn dry and then harvest before the wind and the birds get to
them. For some perennials that self-sow readily
such as mallows, make a note to cut off flowers when done unless you
want many seedlings.

If you
don't have an edging material around the borders of your garden
beds, use a
flat
spade to shave off clumps of sod to delineate the edges.
You'll probably need to do this a couple
of times, but if you don't you'll be fighting encroaching
grass all summer.

To allow
good drainage in your container plantings, raise the pots off the
ground or
deck so water can seep out the drainage holes. This also will reduce
the
staining that can occur when pots sit directly on wooden steps or a
deck. You
can purchase pot feet or plant caddies from garden supply stores, or
make your
own pot feet using flat stones of similar size, rubber bumpers from
the
hardware store, or even old checkers from the game you never play
anymore.

Harvest strawberries
frequently, and remove any that show signs of grey mold or rot
diseases. Not
only are these berries inedible, they quickly spread disease to
other ripening
fruits. Mulch under plants with straw to reduce contact with the
ground where
the disease spores reside.

Growing
grapes? Then you should remove any
flower clusters the first two years after planting. In the third,
and subsequent years, thin
grape clusters when grapes are about 1/8-inch wide, leaving only one
or two
bunches of grapes per new shoot.

If you’re
growing berries, cherries, or grapes, you should get familiar with
their latest
pest—the spotted wing drosophila—a vinegar fly, somewhat like a
fruit fly. The fly lays eggs in ripening fruit, which
hatch into small worms or larvae in the ripe fruit. You can place
large cups with an inch of
vinegar cider vinegar among your berries to trap flies. If just a
few plants or rows of berries,
cover them with a fine netting such as row cover fabric as the fruit
begin to
ripen to hopefully keep the flies away.
There are a couple of organic sprays you might use as well—check
with
your local full-service garden store for available and appropriate
products.

Make
plans to visit local perennial nurseries this summer
(pss.uvm.edu/ppp/vpdgli.html).